How-to Check iPhone Firmware Version

First of all, if you don’t know what is iPhone firmware, see What is iPhone Firmware. It basically the software which is currently running on your iPhone.

How-to check the version of iPhone firmware?
Tap Settings → General → About

Look-up the Version column (between Available and Carrier columns). It is your firmware version.

Look at the example screenshoot of my iPhone firmware version below:

It says: 4.1 (8B117)

It means that my iPhone firmware version is 4.1. Yes, I’m currently running iOS 4.1 on my iPhone, white 8B117 is build version. Some devices has different firmware build version sometimes, although all devices run the same firmware version. However, it rarely happens.